A raindrop of mass 1.00 g falling from a height of 1m hits the ground with a speed of 50ms^(-1)Calculate (a) the lossof PE of the drop (b) the gain in KE of the drop ( c ) Is the gain in KE equal to loss of PE ? If not why ? Take, g =10 ms^(-2)

A raindrop of mass 1.00 g falling from a height of 1m hits the ground

1.	A raindrop of mass 1.00 g falling from a height of 1m hits the ground with a speed of 50ms^(-1)Calculate (a) the lossof PE of the drop (b) the gain in KE of the drop ( c ) Is the gain in KE equal to loss of PE ? If not why ? Take, g =10 ms^(-2)
Answer» Solution :m = 1.00 g ` = 1xx10^(-3) kg` h = 1 km = `10^(3)` m ` g = 10 m//s^(2)` `V = 50 m//s ` (a) Loss in PE = mgh `= 1xx 10^(-3) xx10 xx10^(3)` = 10 J (b) Gain in KE ` = 1/2 MV^(2)` ` 1/2 xx1xx10^(-3) xx(50)^(2)` `=1/2 xx10^(-3) xx2500` `= 1.250 J ` No , gain in KE is not equal to the loss in its PE , because a aprt of PE is used in doing work againstthe viscous DRAG of air .